Opened 11 years ago

Closed 11 years ago

Last modified 11 years ago

#2622 closed defect (fixed)

Difficult to read large one strip G4 GeoTIFF files

Reported by: warmerdam Owned by: warmerdam
Priority: normal Milestone: 1.5.4
Component: GDAL_Raster Version: 1.5.0
Severity: normal Keywords: gtiff
Cc: gaopeng


Large 1bit one strip G4 compressed tiff files can be very difficult to read in GDAL because the entire file is treated as a singe 8bit block making the memory representation 8 times the size of the decompressed 1bit image.

Libtiff can automatically split uncompressed images into smaller blocks but cannot do this for compressed files. So in theory the problem exists for all one strip compressed images but it is much more common for the 1bit compressed files.

Change History (3)

comment:1 Changed 11 years ago by warmerdam

Milestone: 1.5.4
Resolution: fixed
Status: newclosed

I have implemented a new special-case band type - GTiffSplitBitmapBand - which is applied for largish one row, one bit, one band TIFF files in trunk (r15565), and 1.5 branch (r15567). I also added a test case in autotest/gcore/ (r15566).

comment:2 Changed 11 years ago by warmerdam

Cc: gaopeng added

comment:3 Changed 11 years ago by warmerdam

Fix a bug when not starting from the beginning in trunk (r15570) and 1.5 branch (r15571).

Note: See TracTickets for help on using tickets.